Biomed Chromatogr. 2019 Dec 06. e4769
This study was designed to investigate the metabolic and transcriptional alterations in seminal fluid caused by asthenozoospermia (AS). To address these issues, the method of metabonomics based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and real-time quantitative PCR (RT-qPCR) were performed to identify some crucial biomarkers and transcription levels of the enzymes in seminal fluid. Seminal fluid samples were collected from 87 AS patients and 73 healthy males with normozoospermia (NZ). The quantitative analysis by UPLC-MS/MS showed that 19 metabolites in seminal plasma were associated with AS, and they were involved in several metabolic pathways, such as energy metabolism, purine metabolism, methionine cycle, and branched chain amino acid (BCAA) metabolism. Among these metabolites, the levels of citric acid, malic acid, succinic acid, and pyruvic acid, which are related to energy metabolism, were collectively reduced in the AS group, while the lactic acid level was enhanced. The results indicated that lesser energy source (adenosine triphosphate, ATP) was produced through the anaerobic glycolysis pathway rather than aerobic catabolism of sugar and tricarboxylic acid (TCA) cycle, resulting in deficiency in the power of sperms. Meanwhile, significant differences in metabolic profiles between the AS group and the control group were revealed on partial least squares discriminant analysis (PLS-DA). In addition, RT-qPCR results revealed that the expression levels of 4 genes coding fructokinase (FRK), citrate synthase (CS), succinate dehydrogenase (SDH), and spermine synthase (SMS), which were related to energy metabolism, were decreased in the AS group. The 23 descriptors of differential expression in AS may be valuable for the diagnosis and sequential study on AS. These results will help to highlight the role of sperm inactivity in AS pathogenesis.
Keywords: RT-qPCR; UPLC-MS/MS; asthenozoospermia; seminal fluid; tricarboxylic acid